[PHP知识库]PHP计算附近距离

/**
 * 圆周率
 * @param $lat1 自己的经纬度22.xx
 * @param $lng1 自己的经纬度108.xx
 * @param $lat2  目标的经纬度22.xx
 * @param $lng2  目标的经纬度108.xx
 * @param int $len_type
 * @param int $decimal
 */
 public static function getRatio($lat1, $lng1, $lat2, $lng2, $len_type = 1, $decimal = 2)
{
    $radLat1 = $lat1 * PI ()/ 180.0;
    $radLat2 = $lat2 * PI() / 180.0;
    $a = $radLat1 - $radLat2;
    $b = ($lng1 * PI() / 180.0) - ($lng2 * PI() / 180.0);
    $s = 2 * asin(sqrt(pow(sin($a/2),2) + cos($radLat1) * cos($radLat2) * pow(sin($b/2),2)));
    $s = $s * 6378.137;
    $s = round($s * 1000);
    if ($len_type == 1)
    {
        $s /= 1000;
    }
    return round($s, $decimal);
}